Non boot after xp install

Hi all i wonder if you can help. I managed to shrink my drive in vista and create a new drive using the xp boot disk to install xp. After i installed xp my pc restarted only to get stuck during boot. It will still boot from cd but i now will not boot from my HD either xp or vista. I have no problem accessing and formatting the drive nd partition in the xp boot disk but it just wont boot even to xp.
Can i fix this? Has anyone heard of this before?
Thanks in advance.

I can enter bios but f8 does not work. The PC hangs after trying to boot from cd. I am thinking that xp does not have the drivers to boot from HD. I dont have a recover disk for vista so am kind of stuck. Would i be able to restore Vista using an installation disk?.
xp did not install, i used the xp cd to boot then install from there. It got as far as preparing for install and rebooting, this is when the problem occured.

My thimbles worth of knowledge might help or confuse. I am experiencing the same problem as you have described and the only savings so far is to be able to get windows vista to run is tapping F11 (System Recovery I believe). I also am not able to get F8 to work unless I'm in the Safe Mode which I can get into from System Recovery. I frantically backed up computer, created my recovery discs which you can do one time with HP...pretty easy step which I should have done within the first few days of owning machine (HP A6142N). Currently I'm close to reinstalling Vista which I'm very hesitant in doing. All the programs I've installed over the past few weeks I'll have to reinstall. Not sure if I've supplied any helpful info. except to say you'll not alone...my computer hung up right about where you describe.